code: def extract_timestamp(self, value: Any, record_timestamp: int) -> int:
      return int(value[0])
  
file_path: flink/flink-end-to-end-tests/flink-python-test/python/datastream/data_stream_job.py
imports: from typing import Any
  from pyflink.common import Duration
  from pyflink.common.serialization import SimpleStringSchema
  from pyflink.common.typeinfo import Types
  from pyflink.common.watermark_strategy import TimestampAssigner, WatermarkStrategy
  from pyflink.datastream import StreamExecutionEnvironment, TimeCharacteristic
  from pyflink.datastream.connectors import FlinkKafkaProducer, FlinkKafkaConsumer
  from pyflink.datastream.formats.json import JsonRowDeserializationSchema
  from pyflink.datastream.functions import KeyedProcessFunction
  from functions import MyKeySelector
label_desc: Use image node_id 1 for calling the KafkaRowTimestampAssigner obj's underlying member method code with example usage: obj.extract_timestamp(value, record_timestamp) and returns: int